In the art of air filtration it is well known to provide an expanse of air filtering medium that is formed into a disposable full-face filtration mask which covers the nose and mouth of a user to thereby filter the breathing air which reaches the user's lungs. Such a mask typically includes an elastic band or similar fastner to secure the mask to the user's face, as well as rigid support elements which are secured to the mask to cooperate with portions of the user's face (e.g., the bridge of the nose) for support of the mask on the user's face. Such masks typically have been utilized for filtration of particulate matter such as dust entrained in the ambient air.
Other known filtration masks include a permanent mask (as opposed to the above characterized disposable type) with canisters that hold replaceable filtration elements. These masks ordinarily are supplied with filtration elements according to the specific type of material to be filtered from the breathing air. For example activated charcoal filter elements will be utilized in such canister type masks to filter certain chemical pollutants from the breathing air, or a filter element saturated with a suitable chemically effective substance may be utilized to chemically absorb or neutralize pollutants in the ambient breathing air.
Such prior art filtration masks as above described have been recognized primarily for use in overcoming the harmful effects of long term exposure to dust or vapor pollutants in the ambient air which might be encountered in any number of industrial or other workplace environments. As such, the prior art of such filtration masks has not contemplated uses where other significant parameters of the air filtration equipment such as minimal use of storage space, ease of quick emergency deployment and use, and minimal equipment weight would be significant factors.
In the commercial airline industry, such parameters become extremely important as unnecessary weight and bulk of equipment carried on an aircraft directly impact on the aircraft payload and therefore the profitability of each flight. In addition, emergency circumstances in commercial aircraft travel may dictate that individual travelers having no experience in emergency procedures nevertheless be able to quickly deploy and use emergency equipment to facilitate their escape, or rescue of them from an aircraft. For example, in recent test crashes as well as in at least one real aircraft fire, it was found that a great many serious injuries or passenger deaths in an aircraft fire result not from burns but inhalation of smoke and toxic gases generated by combustion of materials inside the aircraft. The limited space in an aircraft cabin, and the relatively large number of passengers typically occupying it are two factors which can greatly aggravate the danger to passengers in an aircraft fire. The confines space of the aircraft cabin will fill with smoke and toxic gases very quickly if even a small fire starts. The resultant difficulty in breathing and blinding effect of the smoke can dangerously increase the sense of panic in the aircraft cabin and/or quickly disable the occupants, and thereby reduce or completely eliminate any possibility of an effective rescue operation.
In the prior art there has not been known any completely satisfactory means or providing aircraft passengers with a mode of short term emergency breathing assistance to allow them time to escape the debilitating smoke and toxic gases of an aircrtaft cabin fire.